Class AffinityFunctionBase

Base class for predefined affinity functions.

Inheritance
System.Object
AffinityFunctionBase
RendezvousAffinityFunction
Implements
Namespace: Apache.Ignite.Core.Cache.Affinity
Assembly: Apache.Ignite.Core.dll
Syntax
public abstract class AffinityFunctionBase : object, IAffinityFunction

Fields

DefaultPartitions

The default value for Partitions property.

Declaration
public const int DefaultPartitions = null
Field Value
Type Description
System.Int32

Properties

ExcludeNeighbors

Gets or sets a value indicating whether to exclude same-host-neighbors from being backups of each other.

Declaration
public virtual bool ExcludeNeighbors { get; set; }
Property Value
Type Description
System.Boolean

Partitions

Gets or sets the total number of partitions.

Declaration
public virtual int Partitions { get; set; }
Property Value
Type Description
System.Int32

Methods

AssignPartitions(AffinityFunctionContext)

Gets affinity nodes for a partition. In case of replicated cache, all returned nodes are updated in the same manner. In case of partitioned cache, the returned list should contain only the primary and back up nodes with primary node being always first. Note that partitioned affinity must obey the following contract: given that node

N
is primary for some key 
K
, if any other node(s) leave

grid and no node joins grid, node 

N
will remain primary for key 
K
.

Declaration
public virtual IEnumerable<IEnumerable<IClusterNode>> AssignPartitions(AffinityFunctionContext context)
Parameters
Type Name Description
AffinityFunctionContext context

The affinity function context.
Returns
Type Description
IEnumerable<IEnumerable<IClusterNode>>

A collection of partitions, where each partition is a collection of nodes, where first node is a primary node, and other nodes are backup nodes.

GetPartition(Object)

Gets partition number for a given key starting from 0. Partitioned caches should make sure that keys are about evenly distributed across all partitions from 0 to Partitions for best performance.

Note that for fully replicated caches it is possible to segment key sets among different grid node groups. In that case each node group should return a unique partition number. However, unlike partitioned cache, mappings of keys to nodes in replicated caches are constant and a node cannot migrate from one partition to another.

Declaration
public virtual int GetPartition(object key)
Parameters
Type Name Description
System.Object key

Key to get partition for.
Returns
Type Description
System.Int32

Partition number for a given key.

RemoveNode(Guid)

Removes node from affinity. This method is called when it is safe to remove disconnected node from affinity mapping.

Declaration
public virtual void RemoveNode(Guid nodeId)
Parameters
Type Name Description
Guid nodeId

The node identifier.

Implements